Officials said more evacuation orders were released on Monday for residents of El Dorado following the start of a wildfire over the weekend, which spread overnight.

The blaze, which was labeled as the Caldor Fire, started in the Omo Ranch close to the Sopiago Creek Road on Saturday evening, the U.S. Forest Service El Dorado division said. Officials said the fire has burned at least 750 acres and was not yet contained as of Monday morning.

The evacuation orders were issued by the El Dorado County Sheriff’s Office for residents within a 1.5-mile radius of the Caldor Fire. An evacuation warning was increased on Monday, ordering people in Big Mountain areas and in the Leoni Meadows.

The office on Sunday said communities in the identified area “should be on alert and prepared to evacuate.”

An evacuation center was put up by the sheriff’s office at the Diamond Springs Fire Hall.

The Forest Service said the difficult terrain became a challenge to reach the fire, with more than 280 personnel helping to contain the blaze. Overnight, Caldor Fire has spread on all sides, especially to the east, KCRA 3 reported.

Investigation is ongoing to determine the cause of the fire.